1. Field of the Invention
The present invention relates to an information carrier, an information recording and/or reproducing apparatus, and an information detecting apparatus.
2. Related Background Art
In recent years, there has been developed a scanning tunnel microscope (hereinafter referred to as STM) capable of observing directly the surface of a substance and the electronic structure in the vicinity of the surface [G. Binning et al., Helvetica Physica Acta. 55.726 (1982)], and it becomes possible to observe real space images with a high resolution irrespective of monocrystalline or non-crystalline. Furthermore, there is an advantage that the STM enables a measurement with low voltage while causing almost no damage to a testing material due to its electric current. Also, it can be operated not only in a super high vacuum but in the atmosphere or in a solution, and is applicable to various materials. Hence, its wide range applications are expected.
The STM utilizes a phenomenon that a tunnel current is generated when a metal probe and a conductive specimen are allowed to approach a distance of approximately 1 nm while a voltage is being applied between them. Recently, there have been many proposals put forward for the construction of information processing apparatuses mainly for super-high density recording and reproducing by the utilization of the STM principle such as disclosed in Japanese Patent Laid-Open Application No. 63-161552 and Japanese Patent Laid-Open Application No. 63-161553. In other words, with the probe electrode which corresponds to the STM probe, physical changes are given to a recording medium which corresponds to a specimen, or the electronic condition of the surface of a recording medium is changed to record information, and by the method of reproducing the recorded bit information by the tunnel current flowing between them, it will be possible to perform the recording and reproducing of large scale information in a high density of molecular or atomic order.
In this respect, as one of the above-mentioned recording methods, it is possible to produce holes on a recording medium such as graphite by the application of a pulse voltage in order to give physical deformation, aside from making dents by comprising an acute recording probe on a recording medium according to a recent report. In other words, after setting the probe electrode close to the surface of a recording medium, a voltage is applied between them at 3 to 8V with a pulse width of 1 to 100 .mu.S, thereby to cause a hole of approximately 40 .ANG. diameter to be formed, which is good enough to be used as a recording bit. On the other hand, in order to perform recording by changing the electronic states, there is a known method in which a deposit film of an appropriate organic molecule is formed on the base electrode by Langmuir-Blodgett's technique (hereinafter referred to as LB method) or the like, and a voltage is applied between the base electrode and probe electrode to change the electric resistance properties of the microscopic portion. Attention is given to this method because this method can easily perform erasing and rewriting.
However, in the conventional information recording carrier and information processing apparatus using such a carrier, the recording carrier and the surface of the probe electrode are always exposed to the atmosphere, and by the moisture in the atmosphere and others, there occurs property degradation due to elapsed time. Also, there is a possibility that dust particles in the atmosphere adhere to the probe electrode and recording medium to cause them to be damaged.